首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1268篇
  免费   66篇
  国内免费   7篇
医药卫生   1341篇
  2024年   1篇
  2023年   10篇
  2022年   12篇
  2021年   39篇
  2020年   40篇
  2019年   36篇
  2018年   33篇
  2017年   32篇
  2016年   47篇
  2015年   39篇
  2014年   52篇
  2013年   84篇
  2012年   97篇
  2011年   92篇
  2010年   65篇
  2009年   59篇
  2008年   122篇
  2007年   107篇
  2006年   95篇
  2005年   82篇
  2004年   88篇
  2003年   46篇
  2002年   35篇
  2001年   12篇
  2000年   3篇
  1999年   6篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1994年   1篇
  1988年   1篇
  1983年   1篇
排序方式: 共有1341条查询结果,搜索用时 15 毫秒
91.
ObjectiveTo develop a contemporary profile of infective endocarditis (IE) among a population in 6 counties of Olmsted, Dodge, Mower, Steele, Waseca, and Freeborn in southern Minnesota between 2014 and 2018.Patients and MethodsAll possible and definite cases of IE (≥18 years) among residents of 6 counties in southern Minnesota, including Olmsted County, diagnosed between January 1, 2014, and December 31, 2018, were included in this retrospective, population-based investigation, using the Expanded Rochester Epidemiology Project (E-REP).ResultsOverall, 137 patients with IE developed incident IE in the 6-county region, corresponding to an age- and sex-adjusted incidence rate of 11.9 per 100,000 person-years. Men had a significantly higher incidence of IE (17.9 vs 6.8 per 100,000 person-years), and rates increased exponentially with age in both sexes. The median age of incident cases was 68.2 years, and 67.9% were male patients. The percentage of patients with histories of injection-drug use was low, at 6.7%. Bicuspid aortic valve was the most common (9.6%) native valve predisposing condition. Staphylococcus aureus was identified as the predominant pathogen in the overall group (34.8%), with viridans-group streptococci accounting for only 19.3% cases. Central nervous system and musculoskeletal complications were common. The 30-day readmission rate was 27.9%, and the 6-month mortality rate was 31.8%.ConclusionTo our knowledge, this is the first time that the population-based E-REP has been used to determine an age- and sex-adjusted IE incidence. Older male patients predominated, and S aureus was the most common pathogen. Based on these findings, it is not surprising that IE complications were frequently seen.  相似文献   
92.
Thrombolysis and percutaneous transluminal coronary angioplasty (PTCA) are kinds of procedures that can be used to restore the blood flow of previously ischemic myocardium that can be the result of excessive production of reactive oxygen and nitrogen species, such as superoxide and hydroxyl radical, hypochlorous acid and peroxynitrite. Reaction of urate with some of these potent oxidants results in allantoin production. In this study, we measured the serum allantoin levels, an oxidation product of urate, and "in vivo" marker of free radical generation in reperfusion of ischemic myocardium. After an overnight fasting state, blood samples were collected from 35 patients with coronary occlusive diseases (7 women and 28 men) and 31 healthy subjects (8 women and 23 men). Serum allantoin and urate levels were measured by a GC-MS method. Serum allantoin levels of patients on PTCA therapy (mean+/-SD, 27.4 +/- 15.2 micromol/l) and thrombolytic therapy (24.6 +/- 8.6 micromol/l) were significantly higher than those of the patients without therapy (15.8 +/- 6.2 micromol/l, p < 0.05 with PTCA and p < 0.006 with thrombolysis) and healthy controls (12.6 +/- 6.3 micromol/l, p < 0.002 with PTCA and p < 0.0001 with thrombolysis). Although serum urate levels in PTCA (380.1 +/- 72.6 micromol/l) and thrombolysis (359.5 +/- 60.0 micromol/l) were higher than those in the non-therapy patients (336.6 +/- 53.8 micromol/l) and controls (318.3 +/- 81.0 micromol/l), there were no significant differences among groups (p > 0.05). The results of the study are consistent with others which have demonstrated, higher urate levels are associated with coronary occlusive diseases. Our data support the hypothesis that generation of ROS occurs during myocardial reperfusion. Increased allantoin levels may be used as an index of increased oxidative stress during reperfusion.  相似文献   
93.
Bradbury  Peta  Cidem  Aylin  Mahmodi  Hadi  Davies  Janet M.  Spicer  Patrick T.  Prescott  Stuart W.  Kabakova  Irina  Ong  Hui Xin  Traini  Daniela 《Inflammation》2022,45(3):1209-1223
Inflammation - Grass pollens have been identified as mediators of respiratory distress, capable of exacerbating respiratory diseases including epidemic thunderstorm asthma (ETSA). It is...  相似文献   
94.
Serum cardiac enzyme elevation after percutaneous coronary intervention (PCI), a relatively common complication, is a prognostic determinant of long-term outcome in patients who undergo these procedures. Statins are postulated to reduce such complications. This study investigated the short-term effects of pravastatin on serum creatine kinase myocardial isoform (CK-MB) and serum cardiac troponin I (cTpI) levels after elective PCI. Of 93 patients studied, 72 (77.4%) were men, and 21 (22.6%) were women (mean age, 58.9±11.0 y). Patients were randomly divided into 3 groups before they underwent elective PCI. Preoperatively, group 1 patients (n=30) received pravastatin 10 mg/d, and group 2 patients (n=29) received pravastatin 40 mg/d. Control group patients (n=34) received no lipid-lowering medication. Serum CK-MB and serum cTpI levels were measured preoperatively and then again at 6, 24, and 36 h postoperatively. Demographic features of patients and characteristics of the PCI procedure, including number of vessels/lesions and duration and number of inflations, did not differ among groups (P>.05). Mean serum CK-MB and serum cTpI levels were significantly increased after PCI in all patients (P<.001). When compared with control group patients, those given pravastatin did not experience significantly lowered postprocedural serum CK-MB or serum cTpI levels (P>.05). Preprocedural pravastatin therapy at dosages of 10 mg/d and 40 mg/d seems inadequate for preventing serum cardiac enzyme elevations during short-term follow-up after PCI. Additional research on this topic is recommended.  相似文献   
95.
The myocardial performance index (MPI) reflects global ventricular function. Chronic hypervolemia and uremia may negatively affect the myocardium of both ventricles. The aims of this study were to investigate how chronic renal failure (CRF) affects biventricular MPI and to determine whether preload reduction by hemodialysis (HD) affects left ventricular MPI (LVMPI) and right ventricular MPI (RVMPI) in CRF. Twenty-one patients with CRF (group 1) were examined 1 hour before and 1 hour after an HD session and 1 7 healthy control patients (group 2) were examined once by echocardiography. The MPI for each ventricle was calculated as the sum of isovolumic time intervals divided by the ejection time. Before HD, the LVMPI of group 1 was similar to that in group 2 (P≫.05), but the RVMPI of group 1 was significantly higher (P=.007). After the HD session, LVMPI and RVMPI remained unchanged (P>.05 for both). The LVMPI and RVMPI were not correlated either before or after HD in group 1 (P>.05 for both), whereas they were correlated in group 2 (r= 0.671, P=.003). Chronic renal failure causes isolated RV dysfunction, as reflected by increased RVMPI values. Preload reduction by HD does not affect LVMPI or RVMPI. Patients with CRF also do not exhibit the correlation of LVMPI and RVMPI that is observed in healthy individuals.  相似文献   
96.
The presence of inflammation and demyelination in a central nervous system (CNS) biopsy points towards a limited, yet heterogeneous group of pathologies, of which multiple sclerosis (MS) represents one of the principal considerations. Inflammatory demyelination has also been reported in patients with clinically suspected primary central nervous system lymphoma (PCNSL), especially when steroids had been administered prior to biopsy acquisition. The histopathological changes induced by corticosteroid treatment can range from mild reduction to complete disappearance of lymphoma cells. It has been proposed that in the absence of neoplastic B cells, these biopsies are indistinguishable from MS, yet despite the clinical relevance, no histological studies have specifically compared the two entities. In this work, we analyzed CNS biopsies from eight patients with inflammatory demyelination in whom PCNSL was later histologically confirmed, and compared them with nine well defined early active multiple sclerosis lesions. In the patients with steroid‐treated PCNSL (ST‐PCNSL) the interval between first and second biopsy ranged from 3 to 32 weeks; all of the patients had received corticosteroids before the first, but not the second biopsy. ST‐PCNSL patients were older than MS patients (mean age: ST‐PCNSL: 62 ± 4 years, MS: 30 ± 2 years), and histological analysis revealed numerous apoptoses, patchy and incomplete rather than confluent and complete demyelination and a fuzzy lesion edge. The loss of Luxol fast blue histochemistry was more profound than that of myelin proteins in immunohistochemistry, and T cell infiltration in ST‐PCNSL exceeded that in MS by around fivefold (P = 0.005). Our data indicate that in the presence of extensive inflammation and incomplete, inhomogeneous demyelination, the neuropathologist should refrain from primarily considering autoimmune inflammatory demyelination and, even in the absence of lymphoma cells, instigate close clinical follow‐up of the patient to detect recurrent lymphoma.  相似文献   
97.
Stroke is a multifactorial disease caused by the combination of certain risk factors and genetic factors. There are possible risk factors having important role in the pathogenesis of stroke. The most important environmental factors are cigarette smoking and oxidative stress which have different sources. GST (M1, T1, P1) have major roles in detoxification of the products of oxidative stress and they are polymorphic. DNA damages can also be repaired by repair enzymes such as OGG1 and XRCC1 which are highly polymorphic and have pivotal roles in repair systems. In the present study, we investigated that polymorphisms in genes involved in detoxification and DNA-repair pathways might modify the individual’s risk for ischemic stroke. Furthermore, the products of oxidative stress and antioxidant capacity were measured and the impact of gene polymorphism on them was evaluated. Our data showed that OGG1 Ser326Cys and XRCC1 Arg399Gln gene polymorphisms had impacts on the development of stroke.  相似文献   
98.
99.
100.
Background and objectives: IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide. Accurately identifying patients who are at risk for progressive disease is challenging. The extent to which histopathologic features improves prognostication is uncertain.Design, setting, participants, & measurements: We studied a retrospective cohort with biopsy-proven IgAN in Calgary, Canada. Renal biopsies were reviewed by a nephropathologist with histopathologic data abstracted using a standardized form. The primary outcome was the composite of doubling of serum creatinine, ESRD, or death. Spline models defined significant levels of interstitial fibrosis, glomerulosclerosis, hypertension, proteinuria, and creatinine. The prognostic significances of clinical and histopathologic parameters were determined using Cox proportional hazards models.Results: Data from 146 cases were available for analysis with a median follow-up of 5.8 years. Greater than 25% interstitial fibrosis, >40% glomerular sclerosis, and a systolic BP >150 mmHg were risk thresholds. In univariable analyses, baseline creatinine, proteinuria, systolic BP, glomerular sclerosis, interstitial fibrosis, and crescentic disease were predictors of the primary outcome. In multivariable models adjusted for clinical characteristics, interstitial fibrosis (hazard ratio [HR]2.7; 95% confidence interval [CI] 1.2 to 6.0), glomerular sclerosis (HR 2.6; 95% CI 1.2 to 4.5), and crescents (HR 2.4; 95% CI 1.2 to 5.1) remained independent predictors of the primary outcome and significantly improved model fit compared with clinical characteristics alone.Conclusions: Baseline histopathologic parameters are independent predictors of adverse outcomes in IgAN even after taking into consideration clinical characteristics. Relatively small degrees of interstitial fibrosis confer an increased risk for progressive IgAN.IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Patients with IgAN have a variable clinical course with between 6 and 43% progressing to ESRD over 10 yr (15). Given this variability, identifying reliable prognostic factors is important to help stratify clinical monitoring and treatment regimens.Previous studies have identified clinical features including high-grade proteinuria, reduced kidney function, and hypertension at the time of diagnosis as predictors of adverse outcomes (47). Studies have identified interstitial fibrosis and glomerular sclerosis as poor prognostic features (810). This is not surprising considering that these features are a common final result of damage from glomerulonephritis; however, histopathologic features frequently correlate with serum creatinine, and whether they add prognostic values beyond the measurement of serum creatinine is uncertain. Histopathologic features are commonly categorized on the basis of arbitrary thresholds to denote significant degrees of damage (3,5,11), a factor that may contribute to poor performance in multivariable models of risk prediction in IgAN and result in an underestimation of their ability independently to predict outcomes. We performed a retrospective study using detailed baseline clinical data and quantitative analysis of renal biopsies, including the degree of interstitial fibrosis and glomerulosclerosis, to assess the factors that determine adverse outcomes including chronic kidney disease (CKD) progression and death.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号